Rotor for self-starting synchronous electric motors for clocks and the like



Dec. 18, 1934. A HAIGIS 1,985,091

ROTOR FOR SELF STARTING SYNCHRONOUS ELECTRIC MOTORS FOR CLOCKS AND THE LIKE Filed Jan. 8, 1931 INVENTOB. 7 6d flagrA f who b' M; ATTORNEY Patented Dec. 18, 1934 ROTOR, FOR

AND THE LIKE NOUS ntno'risrc More Alfred Haigis, Baden, Germany,

Kienzle Taxameter Schwartawald, Germany,

Germany Application January it,

Apparate Al. 33, a corporation oi 115331, Serial! No.

In Germany Novemleer 5, rest 4 Claims.

The present invention relates to self-starting synchronous motors, and more particularly to improvements in the armatures, or rotors, of synchronous motors employed to operate horological devices. 7

In some types of synchronous motors the rotor construction is such that, upon starting, the lines of force of the alternating current field are caused to cut through the permanent magnetic poles of the rotor, thereby permanently weakening the magnetism of the rotating armature to an undesired degree. To overcome this diffi culty, and to obtain additional advantages, ir' perfect, or incomplete, magnetic shunts are provided, according to the present invention, between the permanent, magnetic poles of a synchronous motor armature.

In addition to the main objects of the present invention as stated heretofore, it is an imp artant object of this invention to provide a synchronous motor construction wherein the useful field in the motor consists only of a residual stray, or leakage, field of the armature for which the permanent magnetism in the steel armature constitutes a storage, or reserve, force, the imperfeet, or incomplete, magnetic shunts being in the form of soft iron pieces, either separate or in unit assembly, or being arranged in disc form coordinated to the rotor.

Another object of the invention is to provide shunts between the poles of a synchronous motor armature, which shunts may be cup-shaped, if desired, disposed in a ring form about the periphery of the said armature.

Still other objects of the invention are to in1- prove generally the efliciency of synchronous motors, and to particularly provide a synchronous motor construction for horological devices which is not only durable and reliable in operation, but economically assembled.

The novel features which are believed to be characteristic of this invention are set forth particularly in the appended claims, the invention itself, however, as to both its organization and method of operation will best be understood by reference to the following description taken in connection with the drawing in which there are indicated several arrangements whereby the invention may be carried into effect.

In the accompanying drawing,

Fig. 1 is a plan elevation of a synchronous motor armature, embodying the present invention;

Fig. 2 is a front elevation of the armature in Fig. 1;

(m. lltit lwl 3 is a plan elevation of a modified form of the invention;

Fig. 42 is a section taken on line looking in the direction of the arrows.

Ref rring to the accompanying drawing where in like characters of reference indicate t e same parts the different views, there is shown Figs. ii and 2 suificient detail to enable one skilled in the electric clocl: to understand the present invention. The conventional synchronous rotor 10 shown these two figures, as well Figs. 3-8 :u' lusive, as seated upon the shaft iii of synchronous motor rotor which itseif not shown.

To accorn iish the objects oi? the inve on, cylindrical pm i? made of soit iron material is partially driven into the pole gaps 17' provided h ween adjacent pairs of north and soot magnetic ,ts between the adjacent utor poles, and as the pins are soi iron a: d

conductive Without possess i; an,

t magi. tic force, they are 1 neutra shunts.

very small,

As active c oss er, in the modification. in g so, also of cylindrical shape, are secured upon a circular carrier 1Q spaced from the rotor dish The pins 18, in this case, disposed laterally in the pole gaps .l'l' the rotor with the r sult that magnetic shunts are created between the poles.

The operation of the present n should. be obvious scription.

is so high that the poles it and is outside these shunts are still ahie to set up leakage fields, these losing of such so e one hand, the desired torque will still obtain able with the motor running at syncln onous speed, and that, on the other hand, self-starting of the motor may not be disturbed. will he, further, appreciated that by means of the ar rangements illustrated in Figs. 1 to 4, the finer lines of the alternating current field of the stator, are enabled to find a path by Way of the shunts between the poles, should they happen he opposite the polarity o? the permanent magnetic rotor and encounte" a corresponding reluctance the instant of the syncln'onous rotor, The oi rotor,

as will be seen, will not be weakened in such cases.

It should, also, be noted that another feeble useful stray field is constantly strengthened by the magnetic storage, or reserve, residing in the strong magnetic potential difference of the main flux between adjacent rotor teeth.

While there has been indicated and described several arrangements for carrying the invention into effect, it will be obvious to those skilled in the art that the invention is by no means limited to the particular organizations shown and described, but that many additional modifications in the arrangements may be used without departing from the scope of my invention as set forth in the appended claims.

What I claim is:

1. A rotor assembly, for a synchronous motor, comprising a shaft, an armature provided with spaced, constant unlike pole pieces aflixed to the shaft, one or more disks disposed on said shaft in spaced relation with said armature, and soft iron elements carried by the disk and disposed between the pole pieces.

2. In combination, a shaft; a circular diskshaped permanent magnet rotor thereon having deep radial slots therein forming a small central hub and a plurality of sector-shaped alternated pole pieces of unlike polarity extending from the hub; and soft iron pins snugly received in the outer ends of said slots respectively and forming imperfect magnetic shunts between the pole pieces.

3. In combination, a shaft; a circular diskshaped permanent magnet rotor thereon having deep radial slots therein forming a small central hub and a plurality of sector-shaped alternated pole pieces of unlike polarity extending from the hub; a carrier disk coaxial on said shaft spaced from the rotor; and soft iron pins carried laterally on the disk parallel to the shaft and received snugly in the outer ends of said slots respectively, forming imperfect magnetic shunts between the pole pieces.

4. A rotor for a self-starting synchronous n1otor for clocks and the like, comprising a magnetic armature having spaced pole pieces of constant unlike polarity, and imperfect neutral magnetic shunts provided between the armature pole pieces so that the useful field in the motor consists only of the residual leakage field of the armature; the said shunts comprising pin-shaped, soft-iron ele ments, a disk associated with the armature, said pins being mounted on the disk and being disposed in the spaces between the armature pole pieces.

ALFRED HAIGIEE. 

